Vodafone — poor service on every single word

hi... i'm senthil selvan...i'm a postpaid user my no is [protected] i've got a post paid connection which has one of the best STD offer provided by the network while every mid of month i've to pay the half or full amount of the bill, i'm paying more than the billed amount though i'll be disturbed by saying you've reached more than 80% of your credit limit and this month without any intimation my access to the network has been cancelled.
In the evening time no vodafone mobile can work just you will see a message as network busy, please try again later for this knid i we have to keep on calling the person we've to call atleast 15 times then only we can reach them
i've used a automated service of this network to find the bill payment centre in chennai. i heard you'll receive your requested information as message shortly, i've never received till