Mondo provide bad service

So like the salesperson from Mondo told me about zte router that wouldn't cost much since am on a phone contract with mtn which all together would be around 400 rand something since that person said it won't cost so much with the contract I got my router on 18 October 2022 only to find out altogether it was around 929 somewhere around there I couldn't pay that returned the router to near MTN branch was given the number it states that if u returned the router and stuff early u don't get billed these mtn and mondo didn't even notify me to cancel that contract with same number given been paying large amounts of money thinking its the phone contract only to find that you people left it open from November i been trying to cancel the contract for the router up to December which i did problem is why you still billing me for something u told me that's not equivalent to what's been said like R2708 I will not pay this plus i send a query to mondo staff one of them to send a query to mtn to take out my bill you guys **** and mtn said they received nothing like why are you lying!!! Please get this fixed or i am filing a case of ********.