Coventry Building Society is once again struggling to cope with surging demand, as new savers rush to lock in higher interest rates.

Over the past week, Money Mail readers have waited more than 30 minutes for the building society to answer its phones.

Britain's second biggest building society says a record number of savers seeking better returns have swamped its call centre after it upped rates at the start of this month.

It has placed itself among the top payers, offering as much as 3.3 per cent on its online easy-access account — as long as you limit your withdrawals to six a year.

It also pays a top 4.12 per cent on a one-year fixed-rate cash Isa.

But the account causing the real problem is the Loyalty Isa which offers 4.4 per cent fixed for a year to its existing members.

The mutual says the deal has led to phones ringing non-stop.

This is not the first time Money Mail has shone the spotlight on Coventry BS struggling with call wait times.

Last December, the society faced the same problem when its savings rates became more competitive.

Readers found themselves hanging on for up to an hour when phoning for help.

bs2web at the time, the society promised to recruit more staff to cut waiting times. However, it is still unable to offer quick responses.

Money Mail reader Carol Walsh from Nuneaton, Warwickshire, found herself sitting at number 63 in the queue of savings customers waiting to talk to an adviser last Wednesday morning. 

Things had hardly improved by the evening when she tried again to find herself 60th in line.

At 9am the next morning another futile attempt to get through found her at number 58 in the queue.

When our reporters tried to get through on Monday, we found ourselves 105th in the queue, while yesterday at around midday we were still at a despairing number 61.

Last Friday, savers were waiting 21 minutes 59 seconds on average, more than double the ten-minute wait Money Mail expects customers to suffer at worst.

By Saturday this had risen to 30 minutes, 55 seconds.

Yesterday wait times were better. The average was down to 16 minutes, 58 seconds.

Sam Richards, head of customer service at Coventry, says: ‘The number of phone calls we receive each day has more than doubled since we launched our market-leading Loyalty Isa to our two million members.

‘Despite having more people than ever answering the phones, it's meant members have to wait longer than normal.'

sy.morris@dailymail.co.uk