Service Level Agreement with an ISP i.e. Internet Service Provider

I am looking for a sample Service Level Agreement that I can modify and present to our current ISP. This has been necessitated by poor service levels we are currently experiencing after having migrated migrated to broadband on July 1, albeit under the impression that up times would be upwards of 90%. Ordinarily we would have moved to another ISP were it not for Wimax radio equipment that we had bought. The radio is not compatible with other ISP’s setups.

Please help!