Home Internet 100MBPS is absolute garbage. Not even getting 20% of what I'm paying for

Not even getting 20% of what I am paying for. I upgraded my 300GB data contract to the Home Internet 100MBPS with Huawei B535-932a router contract less than 2 weeks ago. I am getting 14mbps on speedtest and this garbage costs me R999 a month for 36 months. On my 5G phone I am getting well over 300mbps with my normal vodacom sim card. I can't even put this 100MBPS plan sim in a phone because it is locked to specific routers. This is utter garbage and almost ****worthy. Best effort service should not apply if my 5G phone with normal sim can produce over 300MBPS. Given this was only done less than 2 weeks ago I want this service cancelled immediately and without penalty and the contract cancelled completely instead of upgraded. I am not going to pay this exorbitant amount of money for a service I am not getting.