(a) Notwithstanding any other provisions of this act, extended benefits paid under the provisions of this article shall be charged to the extent that such benefits are attributable to service in the employ of the claimant's base year employer, (i) to the reserve account balance of a “contributory” employer, and (ii) to the account of a “reimbursable” employer who is liable for payments in lieu of contributions as defined in section 4(g),¹ in the following per centums:

(b) No employers' experience rating account, and no employer liable for payments in lieu of contributions, shall be charged with respect to extended benefit payments which are wholly reimbursed, or to the extent partially reimbursed, to the State by the Federal Government.

(c) No benefits paid under this article shall be charged to the employers' reserve account, provided such employer has been relieved of liability from such benefits under the provisions of section 302(a).⁴