Mariaz
The dates you have included aren't particularly clear
The rule is that the DLA will remain in payment for 4 weeks after a Decision is made on the PIP Claim.
If the PIP Decision was made on or before 29 April then the DLA would have been paid for 4 further weeks and then stopped even if this was before the original end date of 27 May.
If it was made after 29 April then the DLA claim should have been extended to allow payment of the remaining 4 weeks.
Gordon