Shaun Jones, clerk of Chirk Town Council, spoke following a meeting between councillors and representatives from HSBC, who said there was "no silver lining" as the banking giant confirmed it would still be pulling out of its branch in Chirk in April.
Despite being grilled by town councillors, Mr Jones said HSBC remained adamant the branch would close and there would be no consultation.
He said: "They've made it clear this decision is not up for review.
"From a community and town council perspective we've not just sat on our hands, we've certainly made our best efforts to bring them to book so to speak, we've made many representations to them by way of petitions, contacting our politicians and public meetings, so it's extraordinarily frustrating.
"We're a small cog against a huge machine but of course we're in the real world, it's a commercial decision."
Mr Jones said the closure will hit the town's elderly residents the hardest. "The groups of people of a different generation are going to be more hit than others, and yes it's true that the onset of online banking has played some part but online banking does have its limitations," he added.
Mr Jones also said HSBC used the meeting as an opportunity to signpost and point out what other channels are available to residents – including the Post Office at the Spar. The closure comes after the firm announced it will also be shutting its Ruabon branch but has secured a promise that a free-to-use cashpoint will remain.
HSBC has closed a series of branches in Shropshire and Mid Wales in recent years. Branches in Whitchurch and Market Drayton closed earlier this month, and the HSBC at Harlescott in the north of Shrewsbury shut for the last time on Friday.
Last year the bank pulled out of Church Stretton, while in 2012 it closed its branches in Ellesmere and Craven Arms.
Llanfyllin, and Llanfair Caereinion are also among those deemed no longer viable by HSBC and will close on February 12.
A spokesman for HSBC said the Chirk branch had seen a 40 per cent reduction in footfall, and that 81 per cent of contact with the bank was now completed via the telephone, internet or smartphone, and that 97 per cent of cash withdrawals were made via an ATM.
He said: "We never take the decision to close a branch lightly, and we understand it's unsettling for the local community. Unfortunately, with an increase in the use of online and telephone banking over the past few years use of the Chirk branch has fallen significantly, and we've taken the difficult decision to close it.
"We are working with customers who use the branch to help them understand their options, which include being able to use post offices for their day-to-day banking and using local ATMs."
Clwyd South AM Ken Skates also held an emergency meeting with the company after hearing that the banks in Chirk and Ruabon - the two remaining branches in his constituency were shutting.
The Labour AM said: "I share residents' anger over HSBC's decision to close its branches in Chirk and also in Ruabon, which is my local bank. They are rightly furious. So many people rely on these two branches, and they are also vital for local businesses and community groups.
"I have already met with HSBC and asked for certain assurances if the closures are forced through in spite of huge public opposition, and secured a promise that a free-to-use cashpoint will remain in Ruabon.
"I will continue to do all I can to keep vital banking facilities and cashpoints in our area, and have this week requested written confirmation that meaningful concessions will be made. It's the very least the company can do given the way they've treated their customers in Clwyd South."