UNAUTHORIZED NEW CONTRACT ON MY NAME

I received a parcel today and i was informed by the delivery guy that it is from MTN. I then called MTN (135) to find out why did i receive this parcel. i was informed that the contract was processed by Reward.co at Mondo company. I tried to call them but there was no answer and i could not get any help. this is not the first time where Mondo company is doing something like this to me. I did not ask for any contract and I do not remember a single day where I was contacted by their agent and/or where I contacted them to request for this contract. I believe that this is ***** and Mondo (Reward co) should rectify this immediately.