ZTE Router for MTN

I bought an Mtn with ZTE home router that has 100 Gig limit and paid for June as pro rata with July as prepaid. It is frustrating that there are no instructions that comes with it and the consultant that sold me said I just plug in and use. The device connectivity said "Connected without internet". The worst part is I bought it a week ago and even today not connected. Frustratingly the MTN help line I cannot go through to speak to a consultant.

I want a refund and please can MTN come collect it's device as there is no support.