Contract and unreasonable fees

I have a problem with the way things are handled by this business. I took a contract for a mifi router but the delivered a wrong router it was a home router and I was advised that I need to cancel the contract and re-do it/take a new one so I cancelled because I was never advised about any cancellation fee plus it was not my fault but Telkom.

After I cancelled I was billed R800.00 and I mentioned that I cant pay that amount it was not my fault but then I ended agreeing to pay if it can be under an arrangement of paying it monthly but my request was never accepted so now my problem is they blocked my other contract which has nothing to do with the cancelled one funny enough they charging it monthly, December the total amount was R1003 and now January is R1403.00 so I want to know where does this R400 comes from since well all the sim cards are blocked? Reference number is: *** My contact details are: *** Email address: ***