Tata Docomo — unintimated deduction of balance

Hi sir... For the last 4 transactions that i have made... I realised that i used only a part of the balance for calls and the rest got deducted absolutely for no reason and am making it sure that it isn't any offer nor a package for limited days that the balance got deducted because the validity is over. Please do revert back to me with necessary details as of why this is creating a hell here. I really like your services and wish to continue if this is well addressed. If this doesn't seem to be important for you all then it would force me to leave your service behind to get a good one that can serve customers better. Thank you... Would be waiting bac for your acknowledgement!!