who really cares

I got a new ipad by one of mtn's marketing agents. Firstly they gave me a wrong sim card (a micro sim instead of nano sim). Firstly there lines you have to phone ? 3 times to get through to them.For the past 3 days I'm trying to activate the sim so I can use it, but everytime they send me to someone else. They even promise to phone me back 2 times ( staff promissing there supervisors will phone but never happens) - I have phoned them so many times that the system tells me that I have reach my limit to phone them and that they will charge me onwards. Still having no responds and no help with my ipad