You should always replace with like capacitors. Caps can be used for many different things, In some cases swapping to a slightly different rating will cause no harm, while others can cause all kinds of issues.
You made sure the polarity(+/-) was correct right?
was it a 820uf?(they have smaller ones like nf/pf as well).
You can in a pinch add 2 caps together in parallel or series depending on what you want.