I'd ditch your support company then if I was you!
Anyways, how have you configured OTM for the collection? I use Data Buffering + Access to connect to the M1 via the network and pull down the CDR data. All my CDR data then goes into the detail1.img file. Does this file contain any data?
I assume from you mentioning Extension Detail Report that you are using the OTM Telecom Billing System (TBS). You need to make sure you have performed a collection and costing before attempting run a report. My collection is configured to use a script (sl1new.col) and it pulls the information from the detail1.img file and runs it through that script. The costing is a bit more in depth
You can check if the collection or costing has succeeded by going into TBS and selecting Edit > Call Database. This will show the data, and an option to view collected or costed data