Barclays Bank is a British Multinational Bank. It was established in the year 1690. It also provides financial services.
It’s headquarter is located in London, United Kingdom.
Its products include
Retail banking
Commercial banking
Investment banking
Investment management

Barclays is structured into four core business: Personal & Corporate (Personal Banking, Corporate Banking, Wealth & Investment Management), Barclaycard, Investment Banking and Africa.
As you have asked about the Barclays Bank, glynneath branch let me tell you it has been closed permanently.
The nearest branch is of Treorchy
Address:
Barclays bank
100/101 Bute Street
Treorchy
Mid Glamorgan
CF42 6AN
Telephone: 0345 734 5345 (central customer services)

Branch Opening Times:
Opening times

Monday 09:30 - 16:30
Tuesday 09:30 - 16:30
Wednesday 09:30 - 16:30
Thursday 09:30 - 16:30
Friday 09:30 - 16:30
Saturday Closed
Sunday Closed

You can also find the details from Barclays bank website
Go to Barclays Bank website
Scroll down and click on ‘Find A branch), the page open look like




Now enter the address or name of branch and you will get the result.