Pathetic service and they will ruine your name and credit

Took a home router device did not work returned it the next day to mtn ,mondo ensured me no bills were going to come my way they billed me then mtn blocked my account due to the high amount all ****in agents of mondo drops the call refuses to assist me do not take any contract from them my Lawyer is trying to make contact no response they cant do a simple job and email mtn