Lenovo — battery changed during servicing

Address:

New Delhi, Delhi

I submitted my lenovo think pad (E431), serial number (Pf0l4c4) for servicing at unit no. G16, ground floor hemkunt chamber 89, nehru place gst. After i collected it, i found my betterry is performing very poorly. I suspect that service centre has changed my laptop battery. The serial id of current battery is
11s45n1052z1zs5238304p.
Please help me to sort out the problem.