Medihelp says they refunded me, but they never did

Firstly, medihelp put a claim on my statement, for my gynae, for a day that I was never there! Then they re-claimed it again on the correct day. This took forever to sort out, after I had to ask them how many times to fix it. Then they paid money into my account, then asked me to pay some of it back, and they would then pay the difference into my account again. After having emailed them again 3 times regarding this, they came back to me today saying that the amount was paid into my account on the 27th of July. This amount was NOT paid into my account!! I did tell them that I would put them on Hello Peter yet AGAIN if this is not resolved. Maybe now I will get someone to phone me back, and not just send me emails lying to me?!