Hi
@SunsetDawn83, it sounds like you are in the UK is that right?
The NHS services that are offered through IAPT (Improving Access to Psychological Therapies) are short term interventions, on the whole these are the services you can self refer to. They tend to not be able to support with cPTSD as you say due to its complexity and long lasting nature. I find, in the want to help people, they offer what they can which are short term treatments for the more regularly seen issues. It is worth keeping in mind that they are not able to give a diagnosis, this can only be done by a psychiatrist. They do screen for symptoms and offer treatments accordingly but it is not a formal diagnosis. You should be able to ask your GP if you would like a referral to a psychiatrist.
I had a course of Trauma Focused CBT and EMDR though these services which were really helpful so there is lots you can take from their support. You are always able to ask what will happen in the sessions and what will come next. It might be they are able to offer you more support, or refer you on elsewhere, or help you plan next steps.
Being in NHS services can be a bit of a battle to get what you need but there are some really great things they can provide and help with. Stick with it and try and focus step by step.