UNSATISFIED CUSTOMER

I have had a contract with Intellicell since 2019 and since then they have been deducting double the amount of the agreed contract. I thought let me leave it so that I can finish paying off my contract sooner. Then 2 months back I was offered another contract which meant that I was done with the previous contract otherwise they would not have offered me another one. I've had the new phone for a month and it has been locked. I cannot use it. I have contacted them and they told me that I have missed my payment.