Sansui Tablet that is not charging.

My mother bought two Sansui tablet at the above mentioned store at December 2016, in Jan 2016, the other phone started to misbehave by not charging. The she took the tablet back to the store, yes they took it n they said they will fix it which took then more than 2 months for them to come back to her. Early this month which they replaced it the new 1, she never used it cos it was also not charging too, the manager told her that if she experience the very same problem she must not come back. Today I took the phone back to him n he told me that he actually he did us a favour by giving us a new phone. All we need is our money back