It is a very unproffesional outfit. I passed the first assessment day several months ago, and now I am still in the holding pool they say to get the second assessment.
I had the same "problem" after I was told I was through Stage I. Other guys were called in for Stage II but not me. Sent and email to HR and got an interview booked within a week with apologises for my 1st email follow-up gone lost in the system.
I suggest you use your time to make contact with BT rather than whine here on PPrune.
Regards
DK