Issue with bill

Location/place: Chandigarh

Name of company/service: Matrix cellular

I bought a sim from matrix for singapore which was activated from 28 june to 3 july 2013 as i was going to singapore for holidays from these days only.. While buying the sim card , matrix dealer dayashankar informed me of all the details regarding call charges etc.. He gave me some extension which i had to use while making calls to india from singapore so that call rates get cheaper .. This is called budget dial.. But this extension did not work there.. So i had to make calls using normal dialling which were very expensive.. Secondly, in the bill generated by the company there are number of calls to the number 1389, when i had not make any call on this number.. They charged me for these calls also.. Thirdly, my connection had to end on 3 july.. N there bill cycle is from 4 to 3.. Today on 8 august i received another bill from 4 july to 3 aug .. Which shows only calls made on the number 1389, when i was in the bangkok from 3 july to 7 july and using bangkok sim.. This matrix sim was not even in my cell phone.. So how can i make calls to that number.. Also after my first bill when i had the issues i called customer care and they said i have made calls to that number, they cannot waive off my bill.. Also when i asked about that budget dial thing.. They said they cannot do anything now as bill is generated.. Also the dealer from which i bought the sim card for Singapore ( dayashankar 9988601434) stopped picking my calls when i told him about the issue with the bill.. In starting i gave him my credit card number as he told me he want to swipe my card and take 100 rs security.. And when the bill generated, even when i had issues with the bill they deducted the amount immediately from my credit card which was in the bill..
My singapore matrix sim no. 96419050
Please help me with this issue..!!