Feedback please

I need feedback. In December I ordered a dual Sim phone which was delivered in January but upon arrival it was an incorrect order single Sim, I called and informed them, they said they can't do an exchange as they do not have dual Sims anymore I would need to cancel and create a new order of a different phone, they arranged for collection of the device.

Fast forward to June I realize the bill on my account was 2600 instead of 320 I called numerous times no one was able to tell me what is going on, I was to wait till the first of July then I called only to be told I was charged a cancellation fee,

How do I get charged cancellation fees because I returned the phone within 5 days after delivery and It wasn't my fault that the wrong phone was delivered? Why am. I not getting feedback on the calls and emails I hv been sending?

Why does no one directs me to a person who can resolve this,?

I can not be paying over 2000 for a phone I never used.