Mtn shocking service after contract signed

Incredibly shocking service. Cancel cell c contract and move to mtn with promises that there coverage is the best. Guarantees verbally that the home wifi option will be as quick as wife's mtn cell phone contract 4g. Eventually get the cheapest possible router they could supply a client. Get home and lone behold, barely get 3mbps. Connection is lost every 15 min for the entire day. Two months later into a 2 year contract and I can do absolutely nothing. I am losing income due to this, and they will not help me. Incredibly disgusted in mtn. Would not recommend then if they were the only supplier.