Well this sounds all too familiar to me!!
My dd is 22 months and about 2/3 months back had a bad cold/teething. I blindly slipped into a habit of going in, being nice and just answering her calls (but not picking her up, or taking her out of the cot) This carried on for a few weeks until I realised she had me trapped into waking up 3-4 times a night. Doing the same calling, "mummy, mummy" in a cute voice. It was driving me mad the lack of sleep and I decided I HAD to put an end to it!!
It confused me a first as I racked my brain for reasons as to why she was suddenly waking up so often. Was it coldness/growbag problems/needed a duvet/nightmares/pain. Then I suddenly figured out that she had gotten clever and thought I was on tap 24/7. She is a very sweet kind little girl, so I didn't see that in her.
Unfortunately the CC wouldn't have worken for me as all she wanted was to see me and then she went back to sleep. So I had to be tough and let her cry it out. I wouldn't reccommend anyone doing this under the age she is, but it was the only answer for me, get tough and set the boundaries.
The first night I ignored her, and she even decided to call out "daddy" to see if there was a response, she lost her temper and had a good scream. Then after an hour I went in silently, picked up all the toys off the floor, put them in the cot, layed her down and went out, I had to repeat this once again after about 30 mins. Then she decided to give up.
The next night she only screamed for 1/2 hour when she woke up and then gave up.
And after that she slept through!! Apart from a slight cold recently she hasn't stirred hardly at all, and if she has it's been a murmer and back to sleep. Now if she has a cold I keep contact minimal and silent at night now. I'm not getting back into that scenario again.
This was the first time I've ever had to do anything this brutal with her since she was born as shes always been a good sleeper, and it was horrid going through it!! But it worked for us, I can't say it will for you. But a couple of nights of hell is worth it in the long run. She is even much happier in the day now, as the disturbed sleep at night was making her grumpy and sleep too long in the daytime.
Sorry Ive waffled on!!