[MilKyXxdreamXx]

i’ve noticed for japanese writings, it tends to mix with kanji. i don’t know if japanese would called these kanji characters traditional or simplified in english (unlike chinese), but for chinese, there is a difference.
since chinese do not mix any two together, or else it would be unrecognizable or causes confusion for one type of readers.

my point is, does japanese writing tend to mix the two kanjis together? since i’ve come across a writing that someone writes:

当館では電話による勧誘販売は一切行っておりません ... (i clearly do not know what it means in jp, but this is an example.)

for instance: 当 is a simplified character, and 館 is a traditional character.
traditional of 当 would be 當 as for 館 simplified would be 馆.

so i was wondering for japanese does 当 and 當 or 館 and 馆 etc. can mean the same thing. or does 当 never be written as 當 in jp kanji?
for example, i don’t think 当館 can be written as 當館 or 当馆 in jp. if i’m not mistaken [?] since to me the kanjis seems to be a mixed of both types of writings, however i think for jp it’s (natural [?]) to write in both forms?