Think I've upset MIL - was I rude?

[Carpathia]

My MIL had a habit of calling my cell as I was driving home after work.  I wouldn't answer it (it's illegal here and I also just do not feel like talking while I drive.)  Once I told her that she was always calling while I was driving, she adjusted her time and my cell would ring the minute I got in my car at the end of the day.  It would literally be 5 minutes after my workday ended. I felt like she was timing me walking out of the building, across parking lot, getting in the car, etc. I still would not answer my cell.  Then she changed her time of calling to just as I was clocking out of work.  I just stopped answering my phone unless I was already at home for the night. Why? The reason she was calling me at those above mentioned times was because she wanted me to pick up something for her from the store and drop it off to her at her house on my way home.  I have numerous voicemails that say, oh, can you pick up such-and-such and drop it off on your way home?  Thanks!  Bye.  She drives and there is really nothing stopping her from running her own errands.  It was maybe 4 months of this several times a week and me never answering my phone before she caught a clue and stopped calling me.
I say all of this to say, perhaps you just do not answer the phone?  Or if you've answered the phone once and told her you would call her back, then do not answer the phone again?  Let it ring, turn off ringer, take phone off the hook.

That's nuts! I would have enjoyed calling her back just after I got home and saying "Oh shoot, I never check my messages until after I get home. Hey, as long as you're going out, could you grab me some ice cream and drop it off? Thanks!" 

First time I've bemoaned the lack of a 'like' button on forums 

My MIL is getting professional help (DH and I rang her doctor and told him how ill she was getting - she'd been telling him she was fine). She's not chewing up the phone lines in crisis every night, and I'm not a substitute for a professional counsellor - hence ringing her doctor when the conversations became more than just letting off steam or needing a sympathetic shoulder for twenty minutes. Most of the times she calls she's just wanting too see how we are and have a bit of a natter.

I think she rings me partly because she's very neurotic and blows things way out of proportion and I'm the opposite so it's good for her to hear someone saying 'Now slow down and look at this logically..." and also because she genuinely doesn't see anyone such as friends anymore, they've lost touch over the years or passed away. She's basically stuck in a very small flat with only her husband for company (good man mostly but an odd duck) and because of her agoraphobia taking her out is rarely an option. I think I'd be begging for outside contact in her shoes too.

I think the turn-off-phone-during-dinner strategy will stop her calling during mealtimes and since her calling isn't usually a problem unless we're tied up and can't get to the phone it'll solve the problem without making her think we're ignoring her.

[TootsNYC]

In addition to turning off the ringer, consider adding an answering-machine message that says, "We can't come to the phone. If it's between 6 and 8pm, please know that we do not take phone calls during family dinner. Leave a message, so we can call you back when we're free again."

That'll remind her every time she calls that it's dinner time!!!
Maybe she'll start ramping down calls at that time.

[Rohanna]

For all I'm not a fan of some of the changes with IoS6- I *love* the new "Do Not Disturb" feature- love love love! I can set the hours that either no one can call, only certain people can call- or allow repeat calls to go through if they dialed immediately. When the "quiet time" is up, the phone goes back to normal, so there's no forgetting it's silenced. My husband loves it for daytime naps before night shift- he sets it so the local hospital, his work, our kid's school and I can call- and that repeat dialing back will ring through- but he's not bothered by friends who don't know he's on nights, doctors/dentist/mechanic offices, telemarketers, etc. More phones need that feature!