It is a usual practice for each of these providers to send out mailers to remind contract expiry and to entice user to re-contract. Mailers are the best they can do for ordinary consumers as they are the most cost effective.
Unless you are a premium customer who spends above $5k a month on data usage and IDD usages, they wont be bothered to call up. Besides, attention is placed on corporate customers and the larger SMEs.
Believe it or not, even Microsoft is considered a small customer to these operators as the connections they have are all piped in from USA with international leased circuits. A small Indian trading firm may be to them a large customer chalking huge IDD bills.
You want good service to your doorstep, order a satellite connection to your private home or your CEO office above. You will be hearing from a very sweet sales lady once every three months at least. Also, you will be invited to golfing events and probably F1 if you chalk enough mileage to meet the sales lady's quota for the year.