Bio metric letter issue

[Pm007]

Hi,

I have applied for my extension in February, I received my acknowledgment on 15th of feb.
On march 15th HO send me biometric letter and on 16th they send other letter that mentioned earlier biometric letter was send in error and we will send you new bio metric letter in due course.
Now it's almost month from last letter and 2 months from the date I received my acknowledgment. Still I have not received biometric letter.
I have called the 800 number and every time I have been told to wait and no explanation is given why my first letter was cancelled.
Has anyone else faced the same issue and can any one advice what should I do in my case