Phone not working in my area

I recently took out a second contract with these guys for a Samsung galaxy core prime.I live Delft so the phone was not working in this area (the mobile network).Hence I could not use things such as Whatsapp and the Internet.I went to the shop to report this matter and particularly to the consultant who was helping me with the purchase.She just pressed the phone and told us that she had put in a network thing.I explained to her that the phone was not going to work because I knew that she just enabled the mobile network which I could do also.Bottom line is that this ended up in a quarrel between me and her-with her shouting about how this is not her fault.We all knew but I was asking for help and to terminate the contract if I cannot be helped because my other phone is working well enough in this area.She said to call customer care if the network was still not working-we did and the guys were \supposed"to be here to investigate on Tuesday.I also called their contract department to ask them to terminate the contract and I could tell that the agent who helped me was also reluctant to do so.now I'm sitting here with a phone that does not serve what I bought it for."""