It shall be the duty of the Tax Collector to sue for the recovery of all taxes due hereunder not paid when due. Any suit to recover any tax, together with interest and penalties, authorized hereunder, from any vendor, shall be begun within six years after such tax is due or within six years after a return has been filed, whichever date is later; but this limitation shall not apply:
Where suit is brought for the recovery of any such tax, the vendor shall be liable for, and it shall be the duty of the Tax Collector to collect, in addition to the tax assessed against such vendor, the costs of such collection and the interest and penalties provided hereunder.
53 P.S. § 16139