UNAUTHORIZED DEBIT ORDERS !!!

Somebody from elite mobile tried to influence me to buy a laptop from them on contract and i then decided to cancel this before i even signed anything !! i never gave my banking details over the phone or at all or sign any documents when i phoned them about this they told me their computers were offline they cant help me ! i phoned again same story rude lady and this is the second month they have done this i want a refund this is ******* i want to know how they got my banking details without my consent and started this debit orders without me signing anything !!!! if this is sorted out by this week i will be laying charges.