Missing paid for parts

We ordered a part for my mothers Renault Kwid in May 2018 and have now 6 months later still not received the already paid for part. Everytime my mother calls she is either told that the part had to manufactured, is en route to South Africa or more recently in SA but for last month now still not at the branch. I find it ridiculous to believe that a large vehicle company like Renault can't provide a simple "Lock-fuel flap" in 6 months yet we had to pay the over R400 before they did anything or rather nothing. Is there no way this can be resolved? Use a part from a damaged vehicle or from your demo ANYTHING rather than leaving a paying customer wait for SIX months with only excuses? This is all through Westvaal Motor Holdings, Lichtenburg under quote 204826, dated 18 May 2018, by sales person PK Roode at a cost of R414.24 part number RE ********** 52 Lock-fuel flap.