Very rude waitress,food was awful,and the worst coffee ever

I placed a pickup order and had to numerously repeat my orderto the emoloyee. When i arrive i am told my food will be all set in a few minuted so i decide to take care of the bill ($28.05) and add a tip ($6.95). As the waitress is bringing me my togo order she voluntairily admits that the cooks put the wrong gravy on my mashed potaties and says if you would like i could go get u a side of the ORIGINAL gravy i ordered so I respond yes please! She cones back and says there will be an extra charge for the side of gravy.... UMM SINCE WHEN AM I RESPONSIBLE FOR PAYING EXTRA FOR YOU TO FIX MY ORDER?? Furthermire she should have taken the whole side of mashed potates and brought me it back freshly made CORRECTLY..how it was ordered and paid for!! So i just say whatever and go home and call the manager on duty...to sum it up he said it was a misscommunication...what is complicated about an order being wrong...and then tell me i have to pay even more to fix my order that i had ALREADY PAID FOR?!?! I have worked 7 years in food industry before being hired in as a change control analyst for an international company. This is just downright laziness in all aspects of personnel IMCLUDING managment.