Charge me for nothing!!!

My contract was suppose to end but Vodacom never gave the exact date. I had more than 200min left on my contract as well when my data bundle ran out last night I recharged my account with 2gig (R250). This morning I used my phone on calls and internet and all off the sudden there was no service. I restarted my phone and when received a sms that I'm on pay as you go now. I couldn't make a call or even go onto the internet. They said I had to recharge my account. <br> <br> What happened to my data and free minutes? Am I being charged for a months subscription now for using the phone from the 1st till the 21st? Why didn't Vodacom in advance say when they will be doing the switch and not make me recharge my data with 2GB?<br> I honestly feel that I'm being done in here!!!!