Legal Advice on meaning of a clause

I am a Trustee of a SSAS (self administered Pension Scheme). The professional who assist with the SSAS, who is a Trustee, say the clause in the agreement below allows them to take money from the fund to cover their costs and are not reliant on the company who normally pays their costs. This professional is also a limited company.
The clause states " Trustees Remuneration - Any Trustee being a solicitor accountant or other person or body corporate engaged in any profession or business shall be entitled to receive commission and to charge and be paid all usual and professional and other charges for work done by him or his firm in connection with the scheme whether in the ordinary course of his profession or business or not and including acts which a trustee not being in any profession or business could have done personally”.

I am being told I must agree to them being paid from the fund. The clause doess not aappear to em to give them a right to be paid from the fund and I am refusing to do so.