No BRP invitation letter afte 16 weeks in application

[speed14]

Hi all, hope someone can help me here, It has been nearly 16 weeks since i applied for SET (M) and have not received BRP invitation letter yet, I have called UKBA few times but received general answer that they can not see anything on their database regarding my application. Also this week i have contacted them via email, complaint procedure and through my MP, i guess this takes some time to get feedback. I fear that I am already near 4 months and still not completed BRP. Looking at timeline it would take another 2-3 months after BRP, means i have long wait (more than 7 months).

Anyone had similar problem? any suggestion what else i should do?

1. Current visa: Spouse visa
2. Date of expiry of current leave: 10-09-2012
3. Application form used for ILR: SET (M)
4. Number of dependants applying at same time: 0
5. Date application posted: 09-06-2012
6. Date application received at UKBA: 11-06-2012
7. Date payment debited: 15-06-2012
8. Payment mode : CREDIT CARD
9. Acknowledgement letter received: 14-06-2012 (Letter dated 13-06-2012)
10. Biometric letter received: Waiting
11. Date of biometrics Enrollment: Waiting
12. Date of approval: Waiting
13. Date of return of passport and other documents: Waiting
14. Date BRP ILR Received:Waiting