Poor service Mtn & Mondo

Between Mondo and Mtn I have sent multiple messages for them to contact me am in need of a month to month sim deal I just bought a Mtn pocket router it's been like 4 days now I have received any calls from Mtn am disappointed by this what should I do with router. Why unt u guys calling it's do easy to get a sim from other networks. Am Nomusa Nxumalo ***