Disgusting service at Standard Trust

Absolutely disgusted by the service of the Trusts department in dealing with my late mom's estate. We're trying to get a renunciation of executorship but no one answers the phone, or if they do they cannot assist because a colleague is in charge of the matter and is unavailable - for months at a time?! We can't proceed with anything until we get the letter but apparently it takes months to simply answer a phone call.