Anyway to get tax refund urgently?

I'm owed a jot insignificant sum from HMRC due to a PAYE overpayment due to confusion over my tax code in part due to multiple employers (agencies). I attempted numerous times to get this corrected but was unsuccessful before the tax year ended. Due to only working part of the last financial year my financial status has ended up in tatters and I find myself and my family in severe hardship. I am now employed full time but constantly chasing my tail due to a build up of missed payments. I am owed just under £1400 off HMRC which would go somewhay to easing the situation I find myself in and would be grateful if this could be resolved with urgency. If an agent feels it necessary to contact me via email, then please do so. I can provide details of my personal tax account to continue any conversation in private if possible. Regards,

Hi Chris H,
To progress your repayment, please contact us directly by webchat or phone, here:
Income Tax: general enquiries
Thank you.