Faulty phones mobicell Headache

I bought a phone from mobicell last year October and by November the phone started freezing. Sent it back to Mobicell for repair, after nearly 2 months, Mobicell get back to me to say the phone had a contact with liquid. On call with them, they are telling me that anything from stem, or sweets can damage the phone. Now I am being asked to par the same amount I bought the phone in order for the phone to be repaired or I have to pay a fee for regretting repair, else, I will not get the phone back. All this their phones does not last long, when you send for repair they want to collect more money. This is day light *******