As your company in question was using a COCOT and the phone was pulled for lack of revenue, did the company offer to make up the difference between the actual and expected revenue? The company may again try contacting the same COCOT and make that offer.
When offering to make up the difference in revenue, you will need to determine what the COCOT deems is revenue from the phone. If they are only counting coin drop, then offer to make up the difference between the coin drop and the monthly cost of the line. If they count the revenue from 800 numbers, long distance and operator services, then you have the right to ask for a monthly statement of all revenue generated by the phone and then what their minimum expected revenue is for all phones.
The alternative is to pay for the phone line and let the COCOT have all revenue from the phone, which as there are no line costs should increase significantly. The COCOT would have the specs for ordering a line from the LEC or CLEC. Be certain to sign a contract that has all the expectations and costs listed -- saves arguing later.